Add a trailing \ when printing filenames for presubmit checks.

This makes it easier to apply commands to a set of files. For example:

Run the command: svn pset svn:eol-style LF \
  chrome/browser/extensions/extension_accessibility_apitest.cc \
  chrome/browser/extensions/extension_accessibility_api_constants.cc \
  chrome/browser/extensions/extension_accessibility_api.h \
  chrome/browser/extensions/extension_accessibility_api.cc \
  chrome/browser/extensions/extension_accessibility_api_constants.h \
  chrome/browser/gtk/accessible_widget_helper_gtk.h \
  chrome/browser/gtk/accessible_widget_helper_gtk.cc \
  chrome/browser/gtk/accessibility_event_router_gtk.h \
  chrome/browser/gtk/accessibility_event_router_gtk.cc \
  chrome/common/accessibility_events.cc \
  chrome/common/accessibility_events.h

requires just 1 copy-paste.

Review URL: http://codereview.chromium.org/552202

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@37350 0039d316-1c4b-4281-b951-d872f2087c98

presubmit_canned_checks.py

@@ -328,7 +328,7 @@ def CheckSvnProperty(input_api, output_api, prop, expected, affected_files):
       res_type = output_api.PresubmitError
     else:
       res_type = output_api.PresubmitNotifyResult
-    message = "Run `svn pset %s %s <item>` on these files:" % (prop, expected)
+    message = "Run the command: svn pset %s %s \\" % (prop, expected)
     return [res_type(message, items=bad)]
   return []
 

presubmit_support.py

@@ -98,8 +98,8 @@ class OutputApi(object):
       """
       output_stream.write(self._message)
       output_stream.write('\n')
-      for item in self._items:
-        output_stream.write('  %s\n' % str(item))
+      if len(self._items) > 0:
+        output_stream.write('  ' + ' \\\n  '.join(map(str, self._items)) + '\n')
       if self._long_text:
         output_stream.write('\n***************\n%s\n***************\n' %
                             self._long_text)